A power-on-reset circuit with precisely triggered threshold voltages

A power-on-reset (POR) circuit, which is an important block in mixed-signal integrated circuits, is used for the correct initialization of critical logic states in digital blocks of mixed-signal circuits. A POR circuit with precisely triggered threshold voltages is proposed. The circuit is designed in a 0.18 μm CMOS technology with a maximum 4 μA quiescent current. The output signal of the proposed circuit is also used to precisely detect whether the power supply is power-on or brown-out. The proposed POR circuit is insensitive to the power ramping time and tolerant to process variations. At typical corner, the proposed circuit reduces the quiescent current by more than 10x and layout area by 38% compared to the previously published designs.